As for carrots and persimmons you are right, these products are rich in beta-carotene, which also affects eyesight. I think you should also air out your room more often and go for walks without any gadgets, not to be distracted but just to walk around and observe. Take a day like this. You also have a drug guide at https://pocketdrugguide.com/ to help you find medications and information about treatments for various diseases. At least even for general development you need to understand a lot of things.